Hormones tell the cell what to do with energy. A technical discussion by insulin and energy specialist researcher Dr Benjamin Bikman. One of my favorite researchers.

https://www.youtube.com/watch?v=q50XkU0lDeI&t=1818s

"When insulin is elevated, fat cells start to grow".

Bonus Bikman interview:  https://www.youtube.com/watch?v=bm6fE2Wg-V4&t=331s